Implantable ports are designed for patients who require long term access to the central venous system or other internal structures for the administration and/or withdrawal of fluids, including hydration fluids, antibiotics, chemotherapy, analgesics, nutritional therapy and blood products. A catheter is typically inserted to form a path to the vascular system by advancing a distal end of the catheter into a blood vessel while a proximal end is connected to the port that is implanted subcutaneously. The port is generally placed under the skin on the upper part of the chest wall or the upper arm, and allows patients to access the desired body lumen while avoiding repeated needlesticks to the target structure. Power injectable implantable ports offer the additional advantage of providing access for the power injection of contrast agents to enhance imaging, such as Contrast-Enhanced Computer Tomography (CECT) scans, which rely on intravenously administered contrast agents to enhance the visibility of internal structures. The contrast agent is power injected into the blood stream to highlight features that would otherwise be difficult to distinguish from nearby tissues. Thus, power injectable ports provide access for the standard injection and withdrawal of fluids (e.g., for therapeutic purposes) and for power injection of contrast agents to enhance imaging.
Although, it is desirable to use ports which are also suitable for power injection, users must be able to positively identify such ports to ensure they are not accessing a port which is not useable for power injection. The industry has established a “CT” mark, which when viewed under a CT scan, is a standard indication of power injectability. Some existing “CT” identifying technologies known in the field today include a cut-through “CT” design through the port body. The limitation of this design is the space available on the port that would allow for adequate size and visibility of the “CT” lettering. Another disadvantage of cut-through design is that the space could promote tissue ingrowth, which may make it more difficult to remove the port later.
Pad printing the “CT” letters onto the port using radiopaque ink is another existing technology. Radiopaque ink prevents X-rays or similar radiation waves to pass therethrough so that they may be identified in scans. However, the radiopaque ink in these ports is often located on an outer surface of the port, which can be susceptible to damage such as smearing, cracking and fragmenting in the subcutaneous environment, making the marking unreadable. In addition, fragments of ink may migrate, leading to ink integrity issues.
Another CT identifying technology is used in the POWERPORT®, manufactured by Bard Access Systems Inc., Salt Lake City, Utah. The POWERPORT® includes an external metal component with “CT” lettering at the base. However, the “CT” lettering occupies a space on the base of the port where the device labeling is typically placed. Device labeling may include manufacturer and/or lot numbers, which may be helpful in identifying the port. In addition, there is a risk of the external component becoming separated from the device.